Welding Procedure Development Workflow According to EN ISO Standards: A Comprehensive Guide

Aygün Karaköse

1 Jul, 2025 07:33 AM

Welding procedure development is a critical process to ensure quality, safety, and repeatability in welded fabrications. The workflow is governed by international standards such as EN ISO 15607, 15609, 15614, 15610, and 15608, which set requirements for qualification, documentation, and testing of welding procedures. This article outlines a step-by-step roadmap for welding procedure development, from material verification to final approval, tailored for welding engineers and quality professionals.

1. Step 1: Material Certificate Verification and Material Group Selection (EN ISO 15608)

   Before beginning welding procedure development, material verification is essential. Material certificates must be reviewed to confirm chemical composition, mechanical properties, and traceability in accordance with project specifications.

   • Material Certificate Verification includes:
   • Confirming compliance with project and material standards.
   • Checking heat number, batch number, and certificate authenticity.
   • Verifying mechanical properties (yield strength, tensile strength, elongation).
   • Material Group Selection per EN ISO 15608:
   • Materials are classified into groups based on their weldability, chemical composition, and mechanical properties.
   • This classification facilitates selection of appropriate welding parameters and filler materials.
   • For example, steels are divided into groups such as carbon steel, low-alloy steel, stainless steel, etc.

   
   

2. Step 2: Project and Drawing Control, Weld Map and Weld Log Preparation

   2.1 Project and Drawing Control

   • Review project documentation and fabrication drawings.
   • Identify welding joints, base materials, joint types, and welding positions.
   • Extract essential data for weld procedure planning.

   2.2 Weld Map

   • A weld map visually represents all welding joints on the fabrication or assembly.
   • It includes:
   • Joint identification numbers.
   • Location of welds.
   • Welding processes to be used.
   • The weld map aids coordination between engineering, fabrication, and inspection teams.

   2.3 Weld Log

   • A weld log is a detailed record of welding activities.
   • It documents specifics for each weld joint and includes
   • Weld Log Element Description
   • WPS Code Welding Procedure Specification reference
   • Welder ID Qualified welder performing the weld
   • Material Number Base material identification number
   • Wall Thickness Thickness of the material to be welded
   • Pipe Diameter Diameter for pipe welding
   • Joint Details Type of joint (butt, fillet), groove geometry
   • Welding Position Flat, horizontal, vertical, overhead
   • Welding Parameters Current, voltage, travel speed, heat input
   • Date and Time Date of weld executionI
   • Inspection Results Visual and NDT results

3. Step 3: Preparation of pWPS (Preliminary Welding Procedure Specification) According to EN ISO 15609-1

   The pWPS is the initial documented welding procedure, serving as a foundation for qualification.

   3.1 Required Sections in pWPS

   • Base Material and Material Group: As per EN ISO 15608 classification.
   • Joint Design:
   • Refer to EN ISO 9692 series for groove types, root face, root gap, bevel angle.
   • Welding Process Selection:
   • Choose welding process (e.g., SMAW, GMAW/MAG, TIG) based on joint, position, and material.
   • Welding Parameters:
   • Current type and polarity.
   • Voltage, amperage, travel speed.
   • Preheat and Interpass Temperature:
   • Specified according to base material and thickness.
   • Filler Material Selection:
   • Electrode for SMAW: per EN ISO 2560.
   • Wire for GMAW/MAG/MIG: per EN ISO 14341.
   • Shielding gases for GMAW/MAG/MIG, including flow rates.
   • Welding Positions:
   • Defined per EN ISO 6947 (e.g., PA, PB, PC...).
   • Post-Weld Heat Treatment (PWHT):
   • If applicable, temperature and duration.
   • Joint Preparation and Fit-Up:
   • Gap, alignment, root opening details.

4. Step 4: Execution of WPQR (Welding Procedure Qualification Record) According to EN ISO 15614-1

   The WPQR is the actual qualification test of the welding procedure developed in the pWPS.

   4.1 Testing Methods

   • Destructive Tests:
   • Bend Tests: To assess ductility and soundness (EN ISO 5173).
   • Tensile Tests: Measure mechanical strength (EN ISO 4136).
   • Impact Tests: Charpy V-notch test to determine toughness (EN ISO 148-1).
   • Macro and Micro Examination: Assess weld fusion, penetration, and microstructure (EN ISO 17639).
   • Hardness Testing: Check hardness profiles to avoid brittleness (EN ISO 9015).
   • Non-Destructive Tests (NDT):
   • Visual Testing (VT): Overall weld appearance inspection (EN ISO 17637).
   • Penetrant Testing (PT): Surface crack detection (EN ISO 3452-1).
   • Magnetic Particle Testing (MT): Detect surface and near-surface defects in ferromagnetic materials (EN ISO 17638).
   • Radiographic Testing (RT): Internal defect detection via X-ray or gamma-ray (EN ISO 17636).
   • Ultrasonic Testing (UT): Internal defect detection with sound waves (EN ISO 17640).

   4.2 Qualification

   • Tests must be performed on representative test welds made under controlled conditions.
   • Results are compared with acceptance criteria per relevant standards and project requirements.
   • Successful qualification leads to WPQR approval.

5. Step 5: Final Welding Procedure Specification (WPS) Creation

   
   

   • Upon WPQR approval, the final WPS is issued.
   • WPS documents the qualified welding procedure ready for production use.
   • Includes all parameters and conditions validated during qualification.
   • WPS serves as a guide for welders and inspectors.

   6. Summary Roadmap (Flowchart)

   A[Material Certificate Verification] --> B[Material Group Selection (EN ISO 15608)]

   B --> C[Project & Drawing Control]

   C --> D[Create Weld Map & Weld Log]

   D --> E[Prepare pWPS (EN ISO 15609-1)]

   E --> F[Perform WPQR Test Welds (EN ISO 15614-1)]

   F --> G[Destructive & NDT Testing]

   G --> H{Tests Passed?}

   H -- Yes --> I[Approve WPQR]

   I --> J[Create Final WPS]

   H -- No --> K[Review & Modify pWPS]

   K --> E

   The welding procedure development workflow requires strict adherence to EN ISO standards to guarantee quality and compliance. From initial material verification to final WPS issuance, each step builds upon the previous one, integrating project requirements, material properties, welding processes, and rigorous testing protocols. This structured approach supports consistent weld quality, safety, and traceability in industrial applications.